Mikizo Nakai

Total Right Ventricular Exclusion Improves Left Ventricular Function in Patients With End-Stage Congestive Right Ventricular Failure

Background—We developed a total right ventricular (RV) exclusion procedure for the treatment of isolated congestive RV failure. The objective of the present study was to elucidate the effects of a complete removal of RV volume overload (RVVO) on the surgically created single left ventricle (LV). Methods and Results—Three adults (2 arrhythmogenic RV dysplasia, 1 Ebstein) and 5 children (all Ebstein) in NYHA class IV underwent the procedure. The RV free wall was resected from the heart, and the tricuspid orifice was closed. Pulmonary blood supply was obtained by a cavopulmonary connection in 6 patients and a systemic-pulmonary shunt in 2. The LV function was evaluated by 2-dimensional echocardiography 1 month after the surgery. All patients are alive. The paradoxical movement of the interventricular septum and geometry of the LV expressed by its eccentricity (2.1 to 1.2, P <0.01) were normalized after the operation in all 8 patients. LV end-diastolic volumes (59% to 109% of normal value, P <0.01), indexed maximal left atrial area (6.5 to 10.5 cm2/m2, P <0.01), LV ejection fraction (27% to 62%, P <0.01), and cardiac index (2.1 to 3.3 L/min/m2, P <0.05) all significantly increased. Conclusion—Removal of the RVVO by means of the total RV exclusion procedure provides effective volume loading, restores a cylindrical shape, and improves contractile function of the LV, thus leading to increased systemic output.

Beneficial effects of prostaglandin E1 on ischemic colitis following surgery on the abdominal aorta

1 (PGE1) on the intestinal circulation, an experimental dog model of ischemic colitis following abdominal aortic reconstruction was made by ligating the inferior mesenteric artery (IMA) and the internal iliac artery, with the creation of a 50% stenosis in the superior mesenteric artery (SMA). The parameters of enteric ischemia included the blood flow of the SMA, the tissue blood flow in the small intestine and left colon, the mean stump pressure of the IMA (IMAP), and the IMAP/mean systemic blood pressure ratio. With the continuous infusion of 10 ng/kg per minute of PGE1 into the descending thoracic aorta, these values increased significantly on the seventh postoperative day compared with those on the day of operation. These results thus suggest that the continuous intraarterial infusion of PGE1 may reduce ischemic changes in the colon following abdominal aortic reconstruction.

Successful one-stage surgical removal of intravenous leiomyomatosis with cardiac extension in an elderly patient

Intravenous leiomyomatosis is a benign smooth muscle tumor that sometimes spreads to the right heart via the inferior vena cava. A complete surgical resection is necessary to ensure its successful treatment. Surgical removal has been performed safely in middle-aged patients. Here we report a case of successful surgical removal in an elderly woman (age 81 years). The woman was admitted with palpitation and diagnosed as having an intravenous leiomyomatosis with cardiac extension. She underwent a one-stage surgical removal with cardiopulmonary bypass and circulatory arrest. We therefore recommend a one-stage operation, if possible, even in elderly patients.

Recurrent arterial aneurysm rupture of the upper extremity in a patient with vascular-type Ehlers–Danlos syndrome

Arterial aneurysm rupture is one of the most critical complications in patients with vascular-type Ehlers-Danlos syndrome (vEDS). Here, we report a case of recurrent aneurysm rupture successfully treated by endovascular embolization. A 38-year old woman who underwent brachial artery ligation for a ruptured aneurysm was diagnosed postoperatively with vEDS. Impending rupture of a collateral artery aneurysm was encountered 5 months after the initial open surgery. Endovascular embolization with a liquid embolic agent was successfully performed. Given that arterial rupture can occur repeatedly in patients with vEDS, careful life-long follow-up is necessary.

Apico-Brachiocephalic Artery Bypass for Aortic Stenosis With Porcelain Aorta

Apicoaortic bypass for left ventricular outflow tract obstruction has been performed with acceptable mid-term mortality. However, sometimes it is difficult to anastomose the distal end of the conduit to the calcified descending aorta in patients with a porcelain aorta. We report an aortic non-touch modification of the apicoaortic bypass in an 80-year-old woman with valvular aortic stenosis and a porcelain aorta extending from the ascending to abdominal aorta. We performed apico-brachiocephalic artery bypass under circulatory arrest with deep hypothermia. This procedure may become a useful surgical option for patients with a severe porcelain aorta.

Risk factors reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum assisted circuits

OBJECTIVES Open heart surgery without homologous blood transfusion remains difficult in children. The introduction of vacuum-assisted cardiopulmonary bypass circuits to reduce priming volume for pediatric patients has improved the percentage of transfusion-free operations. We retrospectively analyzed blood transfusion risk factors to further reduce blood transfusion requirements after vacuum-assisted circuit introduction. METHODS From March 1995 to June 1996, 49 patients weighing between 5 and 20 kg underwent cardiac surgery with cardiopulmonary bypass at our institution, excluding hospital deaths. We retrospectively analyzed risk factors influencing blood use in 37 patients with no blood priming in cardiopulmonary bypass after introducing a vacuum-assisted system. Factors selected for univariate analysis were age, body weight, cyanosis, preoperative Hb, operation time, cardiopulmonary bypass time, aortic cross-clamping time, and intraoperative and postoperative bleeding volume. Correlation between total bleeding volume/body weight and cardiopulmonary bypass time was studied by regression analysis. RESULTS As risk factors, univariate analysis identified cyanotic disease, longer operation time (> 210 minutes), longer cardiopulmonary bypass time (> 90 minutes), longer aortic cross-clamping time (> 45 minutes), greater intraoperative bleeding volume/body weight (> 4 ml/kg), and greater postoperative bleeding volume/body weight (> 15 ml/kg). Regression analysis showed a significant positive correlation between total bleeding volume/body weight and cardiopulmonary bypass time. CONCLUSIONS Cyanotic disease and long bypass time are risk factors in reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum-assisted circuits. Further efforts are needed, however, to reduce blood transfusion requirements, particularly in these children.

Surgical Repair of Unruptured Aneurysms in an Elderly Man with Takayasu's Arteritis

Surgical Repair of Unruptured Aneurysms in an Elderly Man with Takayasu’s Arteritis Tomohiro Hayashida, Yutaka Yokota, Noriyuki Tokunaga, Mikizo Nakai and Masahiro Okada (Department of Cardiovascular Surgery, National Hospital Organization, Okayama Medical Center, Okayama, Japan) Unruptured sinus of Valsalva aneurysm is a rare anomaly which may be acquired or congenital. We describe a case of a 64 year old man with aneurysms(left : 31 mm, non : 21 mm)of the coronary sinus. The Bentall operation was successfully performed and his postoperative course was uneventful. The histopathology of the aortic wall showed Takayasu’s arteritis. Bentall surgery is a good choice for multiple aneurysms of the Valsalva sinus with aortitis. Jpn. J. Cardiovasc. Surg. 44 : 117-120(2015)

Efficacy of contrast-enhanced ultrasonography in detecting graft rupture sites after abdominal aortic aneurysm repair

Non-anastomotic graft rupture is a rare but critical complication after abdominal aortic aneurysm (AAA) repair. Therefore, identifying the rupture sites is important to perform endovascular stent grafting. A 78-year old man who had undergone Y-grafting for infrarenal AAA before 17 years was referred to our hospital with the complaints of abdominal pain. Computed tomography revealed acute pancreatitis and an enlargement around the grafted abdominal aorta. Contrast-enhanced ultrasonography revealed an extravazation from the graft body 1.5 cm distal to the proximal anastomosis, and endovascular stent grafting was successfully performed. Contrast-enhanced ultrasonography might be useful in detecting the graft rupture.

Rapidly progressing multiple cardiac rhabdomyosarcoma

A 47-year-old asymptomatic woman with heart murmur was referred to our hospital because of a left atrial tumor. No tumor had been found at previous echocardiography performed 6 months before. On examination, her vital signs were normal. Auscultation showed systolic regurgitant murmur and diastolic rumble at the cardiac apex. Electrocardiographical and chest radiographical findings were normal. Transthoracic and transesophageal echocardiography, and chest computed tomography (CT) revealed two cardiac tumors in the heart (Fig. 1). One tumor in the left atrium was attached to the free wall and the lateral portion of both anterior and posterior mitral leaflets (Fig. 1a–c), causing severe mitral regurgitation and stenosis of the mitral inflow (Fig. 1d). Another tumor in the left ventricle involved the anterior papillary muscle (Fig. 1a, b). No pericardial effusion was observed. Although we made a tentative diagnosis of cardiac myxomas, we suspected that the tumors were malignant because of the atypical features. Therefore, we recommended early resection. However, she refused the emergent operation because she had not experienced any symptoms. Thus, we planned to resect them 1 month after the visit. One month later, she was admitted to our hospital for a radical operation. Chest radiography on admission showed pulmonary congestion with bilateral pleural effusion and an enlarged cardiac silhouette. Repeated transthoracic echocardiography revealed enlargement of the tumors and large pericardial effusion (Fig. 2a, b). The mitral regurgitation and obstruction were aggravated by the tumors and restricted opening of the thickened mitral leaflets (Fig. 2c), which seemed to be caused by infiltration of the tumors. Mean pressure gradient through the obstruction was 15 mmHg. Moreover, a new tumor protruded into the pericardial space. The tumor seemed to arise from the left atrial appendage as if the tumor in the left atrium had invaded the left atrial wall (Fig. 2d). Thus, we emergently performed resection of the three tumors after removal of the bloody pericardial fluid and mitral valve replacement. The left atrial tumor of 7 9 5 9 5 cm arose from the free wall around the left atrial appendage and anterior commissure of the mitral valve. The mitral leaflets and the tip were thickened, suggesting infiltration of the tumors. The tumor was resected en bloc with the mitral leaflet. The left ventricular tumor of 3 9 2 9 2 cm involved the anterior papillary muscle. The second tumor was resected with the papillary muscle. The third tumor of 2 9 3 9 5 cm existed in the pericardial space and arose from the outer wall of the left atrium. We therefore resected this tumor with the left atrial wall and reconstructed the left atrial wall using equine pericardium. Y. Yokoi I. Yamadori Division of Clinical Laboratory, National Hospital Organization Okayama Medical Center, Okayama, Japan

One-stage Surgery in Patients with Ischemic Heart Combined with Occlusive Peripheral Vascular Disease.

1991年1月より5年間に10例のCABGと動脈硬化性閉塞病変の同時手術を施行した (AAA合併例は除く). 手術時年齢は平均65.8歳で, 冠動脈グラフト本数は平均2.2本で, 動脈硬化性病変の術式は内頸動脈のTEA2例, 大動脈-鎖骨下動脈バイパス2例, 大動脈-両側総腸骨動脈バイパス1例, 総腸骨動脈 interposition 1例, 大動脈-外腸骨動脈バイパス1例, F-Pバイパス3例 (4本), F-Tバイパス1例であり, 手術時間は平均428分, 体外循環時間は平均121分, 大動脈遮断時間は平均61分であった. 無輸血は4例であった. 手術死亡はPMI合併後緊急IABP挿入肢のMNMSの1例であった. 同時期に施行した待期的CABG単独施行183例と比較検討した. 手術時間, 出血量は同時手術例で多かったが, 手術死亡率, 無輸血率, 挿管日数, 術後入院日数は有意差を認めず, 手術は安全に行われた.